1.\" Copyright (c) 1980, 1991 Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)syscall.2 6.4 (Berkeley) 02/12/93 7.\" 8.Dd 9.Dt SYSCALL 2 10.Os BSD 4 11.Sh NAME 12.Nm syscall 13.Nd indirect system call 14.Sh SYNOPSIS 15.Fd #include <sys/syscall.h> 16.Fd #include <unistd.h> 17.Ft int 18.Fn syscall "int number" "..." 19.Sh DESCRIPTION 20.Fn Syscall 21performs the system call whose assembly language 22interface has the specified 23.Fa number 24with the specified arguments. 25Symbolic constants for system calls can be found in the header file 26.Ao Pa sys/syscall.h Ac . 27.Pp 28.Sh RETURN VALUES 29The r0 value of the system call is returned. 30When the C-bit is set, 31.Fn syscall 32returns -1 and sets the 33external variable 34.Va errno 35(see 36.Xr intro 2 ) . 37.Sh BUGS 38There is no way to simulate system calls 39such as 40.Xr pipe 2 . 41.Sh HISTORY 42The 43.Nm 44function call appeared in 45.Bx 4.0 . 46